Biotin analogs

Case Study Binding of Biotin Analogs to Avidin... 

CASE STUDY BINDING OF BIOTIN ANALOGS TO AVIDIN... 

Nucleic acids can also be biotinylated by nonenzymatic methods with photobiotin, a photoactivatable biotin analog (6), which can be commercially obtained from BRL, Sigma, and other commercial sources I have not compared the suitability of this method of biotin incorporation with that reported here, but expect that the method would be fully acceptable FMC (Rockland, ME) markets an alternate nonradioactive sequence detection kit known as Chemiprobe. The basis of this system is a chemical modification of cytosine residues m the probe DNA. After hybridization, the probe is detected by means of a monoclonal antibody that specifically recognizes the sulfonated DNA. Detection of the bound monoclonal antibody is achieved by means of an alkaline phosphatase-conjugated second antibody. 

Biotin and biotin analogs Infant formula Protein precipitation using concentrated hydrochloric acid neutralization with 6 M NaOH lipid extraction with n-hexane Precolumn Microsorb C18 (15 X 4.6 mm, 5 jam Rainin). Analytical Microsorb C18 (250 X 4.6 mm, 5 /zm Rainin). Isocratic 100 mM phosphate buffer, pH 7.0 + methanol (80 + 20, v/v). 0.4 ml/min. Postcolumn reaction system UV absorbance at 220 nm followed by streptavidin-fluorescein isothiocyanate (2.0 mg/L) knitted open tubular reaction system (10.0 m x 0.5-mm ID) at a flow rate External standardization. 184 Linear range = 0.08-1.00 fjM biotin. LoD = 0.02 /zM or 97 pg biotin at SNR = 3. Repeatability CV 3.5% for biotin in infant formula. 

Another variable to consider in choosing biotinylation reagents is the use of a biotin analog such as iminobiotin that has a moderated affinity constant in its binding of avidin or streptavidin (Section 3.1). Analogs may be useful if release of the avidin—... 

In addition to the general criteria discussed above, each assay technology can also suffer from technology-specific interference of chemical compounds. Auto-fluorescent compounds can interfere with any fluorescence-based readout. In assays that use the biotin-streptavidin interaction, biotin analogs are potential false positives. 

Zav yalov and Dorofeeva have utilized this reduction to synthesize the biotin analogs shown in Scheme 5 ... 

Alkylation takes place predominantly on the less substituted site of dialkylsulfoxides, - and this feature has been used advantageously for the synthesis of biotin analogs bearing a methyl group in the a -position on the thiophane ring (Scheme 92, entry b). °... 

Figure 16.3 The correlation between log(MW) and ligand affinity for the LIE data set by Singh and Warshel. " Graph A shows the correlation for the complete data set. In graph B, the two biotin analogs have been removed from the correlation. Biotin and biotin analogs are known not to follow the correlation between log(MW) and affinity, first noted by Kuntz et al Note that the one outlier in the remaining data is an inactive enantiomer where the active enantiomer lies on the line.

Vesely DL, WormserHC, and Abramson HN. Biotin analogs activate guanylate cyclase. Mol. Cell. Biochem. 60 109—114(1984). 

DM Mock, GL Lankford, JJ Cazin. Biotin and biotin analogs in human urine biotin accounts for only half of the total. J Nutr 123 1844—1851, 1993. 

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